Themed Gallery Walls

Gallery walls are a definite trend at the moment and I'm particularly fond of those based around a certain theme.  For ages, I've had a tear sheet of this image showing a gallery wall of water tower prints.  I think this is amazing.

Here is a couple of other gorgeous examples:

And isn't this one just amazing?

I'd like to try doing a gallery wall of (vintage) images of the moon.  I think I must have seen this somewhere as to be honest, it sounds far to cool to have dreamed it up myself!  My search so far of art.com hasn't yielded quite what I'm looking for.  I've decided the images need to be square which narrows things down a bit.  I like the print below showing the eclipse of the moon in sequence but this is all one print.  Maybe I could cut it up and then do a large frame around each segment? Hmmm...

via art.com